The severity of symptoms varies greatly between individuals; however, all people with autism have some core symptoms in the areas of:
Social interactions and relationships. Symptoms may include
- Significant problems developing nonverbal communication skills, such as eye-to-eye gazing, facial expressions, and body posture.
- Failure to establish friendships with children the same age.
- Lack of interest in sharing enjoyment, interests, or achievements with other people.
- Lack of empathy. People with autism may have difficulty understanding another person's feelings, such as pain or sorrow.
Verbal and nonverbal communication. Symptoms may include:
- Delay in, or lack of, learning to talk. As many as 50% of people with autism never speak.1
- Problems taking steps to start a conversation. Also, people with autism have difficulties continuing a conversation once it has begun.
- Stereotyped and repetitive use of language. People with autism often repeat over and over a phrase they have heard previously (echolalia).
- Difficulty understanding their listener's perspective. For example, a person with autism may not understand that someone is using humor. They may interpret the communication word for word and fail to catch the implied meaning.
Limited interests in activities or play. Symptoms may include:
- An unusual focus on pieces. Younger children with autism often focus on parts of toys, such as the wheels on a car, rather than playing with the entire toy.
- Preoccupation with certain topics. For example, older children and adults may be fascinated by train schedules, weather patterns, or license plates.
- A need for sameness and routines. For example, a child with autism may always need to eat bread before salad and insist on driving the same route every day to school.
- Stereotyped behaviors. These may include body rocking and hand flapping.
Symptoms during childhood
Symptoms of autism are usually noticed first by parents and other caregivers sometime during the child's first 3 years. Although autism is present at birth (congenital), signs of the disorder can be difficult to identify or diagnose during infancy. Parents often become concerned when their toddler does not like to be held; does not seem interested in playing certain games, such as peekaboo; and does not begin to talk. They also may be confused about their child's hearing abilities. It often seems that a child with autism does not hear, yet at other times, he or she may appear to hear a distant background noise, such as the whistle of a train.
With early and intensive treatment, most children improve their ability to relate to others, communicate, and help themselves as they grow older. Contrary to popular myths about children with autism, very few are completely socially isolated or "live in a world of their own."
Symptoms during adolescent and teen years
During the teen years, the patterns of behavior often change. Many teens gain skills but still lag behind in their ability to relate to and understand others. Puberty and emerging sexuality may be more difficult for adolescents and teens with autism than for others this age. Teens are at a slightly increased risk for developing problems related to depression, anxiety, and epilepsy.